Fix layering violation in CPDF_Document::FromFPDFDocument().

fpdfsdk/src/fpdfview.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../core/include/fxcodec/fx_codec.h"
 #include "../../core/include/fxcrt/fx_safe_types.h"
 #include "../../public/fpdf_ext.h"
 #include "../../public/fpdf_progressive.h"
 #include "../../public/fpdfview.h"
 #include "../../third_party/base/nonstd_unique_ptr.h"
 #include "../../third_party/base/numerics/safe_conversions_impl.h"
 #include "../include/fsdk_define.h"
 #include "../include/fsdk_mgr.h"
 #include "../include/fsdk_rendercontext.h"
 #include "../include/javascript/IJavaScript.h"
 
+CPDF_Document* CPDFDocumentFromFPDFDocument(FPDF_DOCUMENT doc) {
+  return static_cast<CPDF_Document*>(doc);
+}
+
 CPDF_CustomAccess::CPDF_CustomAccess(FPDF_FILEACCESS* pFileAccess) {
   if (pFileAccess)
     m_FileAccess = *pFileAccess;
 }
 
 FX_BOOL CPDF_CustomAccess::ReadBlock(void* buffer,
                                      FX_FILESIZE offset,
                                      size_t size) {
   if (offset < 0) {
     return FALSE;
@@ skipping 186 matching lines @@
   CheckUnSupportError(pDoc, err_code);
   return pParser->GetDocument();
 }
 
 DLLEXPORT FPDF_BOOL STDCALL FPDF_GetFileVersion(FPDF_DOCUMENT doc,
                                                 int* fileVersion) {
   if (!fileVersion)
     return FALSE;
 
   *fileVersion = 0;
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(doc);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(doc);
   if (!pDoc)
     return FALSE;
 
   CPDF_Parser* pParser = (CPDF_Parser*)pDoc->GetParser();
   if (!pParser)
     return FALSE;
 
   *fileVersion = pParser->GetFileVersion();
   return TRUE;
 }
 
 // jabdelmalek: changed return type from FX_DWORD to build on Linux (and match
 // header).
 DLLEXPORT unsigned long STDCALL FPDF_GetDocPermissions(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return 0;
 
   CPDF_Parser* pParser = (CPDF_Parser*)pDoc->GetParser();
   CPDF_Dictionary* pDict = pParser->GetEncryptDict();
   return pDict ? pDict->GetInteger("P") : (FX_DWORD)-1;
 }
 
 DLLEXPORT int STDCALL FPDF_GetSecurityHandlerRevision(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return -1;
 
   CPDF_Parser* pParser = (CPDF_Parser*)pDoc->GetParser();
   CPDF_Dictionary* pDict = pParser->GetEncryptDict();
   return pDict ? pDict->GetInteger("R") : -1;
 }
 
 DLLEXPORT int STDCALL FPDF_GetPageCount(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   return pDoc ? pDoc->GetPageCount() : 0;
 }
 
 DLLEXPORT FPDF_PAGE STDCALL FPDF_LoadPage(FPDF_DOCUMENT document,
                                           int page_index) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return nullptr;
 
   if (page_index < 0 || page_index >= FPDF_GetPageCount(document))
     return nullptr;
 
   CPDF_Dictionary* pDict = pDoc->GetPage(page_index);
   if (pDict == NULL)
     return NULL;
   CPDF_Page* pPage = new CPDF_Page;
@@ skipping 228 matching lines @@
   CPDFSDK_PageView* pPageView =
       (CPDFSDK_PageView*)(((CPDF_Page*)page))->GetPrivateData((void*)page);
   if (pPageView && pPageView->IsLocked()) {
     pPageView->TakeOverPage();
     return;
   }
   delete (CPDF_Page*)page;
 }
 
 DLLEXPORT void STDCALL FPDF_CloseDocument(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return;
 
   CPDF_Parser* pParser = (CPDF_Parser*)pDoc->GetParser();
   if (!pParser) {
     delete pDoc;
     return;
   }
   delete pParser;
 }
@@ skipping 212 matching lines @@
       pContext->m_pContext, pContext->m_pDevice, pContext->m_pOptions);
   pContext->m_pRenderer->Start(pause);
   if (bNeedToRestore)
     pContext->m_pDevice->RestoreState();
 }
 
 DLLEXPORT int STDCALL FPDF_GetPageSizeByIndex(FPDF_DOCUMENT document,
                                               int page_index,
                                               double* width,
                                               double* height) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return FALSE;
 
   CPDF_Dictionary* pDict = pDoc->GetPage(page_index);
   if (!pDict)
     return FALSE;
 
   CPDF_Page page;
   page.Load(pDoc, pDict);
   *width = page.GetPageWidth();
   *height = page.GetPageHeight();
 
   return TRUE;
 }
 
 DLLEXPORT FPDF_BOOL STDCALL
 FPDF_VIEWERREF_GetPrintScaling(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return TRUE;
   CPDF_ViewerPreferences viewRef(pDoc);
   return viewRef.PrintScaling();
 }
 
 DLLEXPORT int STDCALL FPDF_VIEWERREF_GetNumCopies(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return 1;
   CPDF_ViewerPreferences viewRef(pDoc);
   return viewRef.NumCopies();
 }
 
 DLLEXPORT FPDF_PAGERANGE STDCALL
 FPDF_VIEWERREF_GetPrintPageRange(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return NULL;
   CPDF_ViewerPreferences viewRef(pDoc);
   return viewRef.PrintPageRange();
 }
 
 DLLEXPORT FPDF_DUPLEXTYPE STDCALL
 FPDF_VIEWERREF_GetDuplex(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return DuplexUndefined;
   CPDF_ViewerPreferences viewRef(pDoc);
   CFX_ByteString duplex = viewRef.Duplex();
   if (FX_BSTRC("Simplex") == duplex)
     return Simplex;
   if (FX_BSTRC("DuplexFlipShortEdge") == duplex)
     return DuplexFlipShortEdge;
   if (FX_BSTRC("DuplexFlipLongEdge") == duplex)
     return DuplexFlipLongEdge;
   return DuplexUndefined;
 }
 
 DLLEXPORT FPDF_DWORD STDCALL FPDF_CountNamedDests(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return 0;
 
   CPDF_Dictionary* pRoot = pDoc->GetRoot();
   if (!pRoot)
     return 0;
 
   CPDF_NameTree nameTree(pDoc, FX_BSTRC("Dests"));
   int count = nameTree.GetCount();
   CPDF_Dictionary* pDest = pRoot->GetDict(FX_BSTRC("Dests"));
   if (pDest)
     count += pDest->GetCount();
   return count;
 }
 
 DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDestByName(FPDF_DOCUMENT document,
                                                     FPDF_BYTESTRING name) {
   if (!name || name[0] == 0)
     return nullptr;
 
-  CPDF_Document* pDoc = CPDF_Document::FromFPDFDocument(document);
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return nullptr;
 
   CPDF_NameTree name_tree(pDoc, FX_BSTRC("Dests"));
   return name_tree.LookupNamedDest(pDoc, name);
 }
 
 DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document,
                                               int index,
                                               void* buffer,
@@ skipping 47 matching lines @@
   if (!buffer) {
     *buflen = len;
   } else if (*buflen >= len) {
     memcpy(buffer, utf16Name.c_str(), len);
     *buflen = len;
   } else {
     *buflen = -1;
   }
   return (FPDF_DEST)pDestObj;
 }